Method of making lock washers



C. G. OLSON METHOD OF MAKING LOCK WASHERS June 12, 1934.

lllllilll Filed Aug. 3, 1933 I'HHHHHHI ill! Hull Patented June 12, 1934UNITED STATES PATENT OFFICE 1,963,027 METHOD OF MAKING LOCK WASHERSIllinois Application August 3, 1933, Serial No. 683,413

9 Claims, (Cl. 10-86) My invention relates generally to methods ofmaking lock washers, and particularly to methods of making lock washersof the overlapping prong type.

One of the important objects of my invention is to provide a simple andpractical method of forming lock washers from a strip of resilient fiatstock, and more particularly to provide a method whereby said stock maybe edgewise formed so as to eilect the overlapping of prongs along theinner margin thereof.

More specifically, my invention contemplates the provision of a methodwhich includes the step of edgewise forming into an annular shape astrip of resilient metal having a plurality of prongs along the marginthereof in such a manner as to thereby effect the overlappingrelationship of adjacent prongs.

Still more specifically, it is an object of my invention to providealong one margin of strip stock a plurality of adjacent prongs, and thenwarp said prongs so as to present work engaging corners on oppositesides of the stock, and thereafter coil or edgewise form said strip soas to efiect overlapping relationship of said prongs in the completedwasher.

A further object of my invention is to form a washer in the manner setforth above, and then secure the adjacent ends of the washer by anysuitable means, such as by spot-welding the overlapping portions of theadjacent prongs at the abutting extremities of the washer stock.

'The foregoing and numerous other objects and advantages will be moreapparent from the following detailed description when considered inconnection with the accompanying drawing, wherein Figure 1 discloses astrip of resilient flat stock, which may be employed in practicing myimproved method of producing washers;

Figure 2 discloses the stock of Figure 1 after it has been split so asto present a plurality of adjacently positioned prongs along one marginof the stock;

Figure 3 is an edgewise view of the strip of Figure 2 after the prongshave been warped so as to present work engaging corners on oppositesides of the washer stock;

Figure 4 discloses the manner in which the strip of Figure 3 is coiledor formed edgewise so as to eifect the overlapping of adjacent prongs;

Figure 5 is a plan view of a completed washer disclosing the overlappingportions of the prongs at the abutting ends of the washer securedtogether by spot-welding;

Figure 6 discloses the washer of Figure 5 after the outer multi-sidedmargin has been formed into a true circle;

Figure 7 is a strip of resilient fiat stock having modified prongs;

Figure 8 is an edgewise view of the strip of Figure 7 after the prongshave been warped out of the plane of the stock;

Figure 9 is a plan view of the washer resulting from the edgewisebending or forming of the strip of Figure 8, disclosing how the curvededges along the inner and outer margin of the strip ultimately conformwith a true inner and outer circle along the margin of the completedwasher;

Figure 10 is a diagrammatic illustration of the manner in which theteeth or prongs of the washer are adapted to initially set up resilientresistance to the clamping action of thework; and

Figurell discloses the manner in which the prongs are finally clampedagainst each other as a result of the tightening of the work piecethereagainst.

Referring now to the drawing more in detail wherein like numerals havebeen employed to designate similar parts throughout the various figures,it will be seen that Figure 1 discloses a strip of resilient fiat stockdesignated generally by the numeral 12. This material conforms to therequired degree of resiliency and strength for the particular washer tobe formed therefrom. One embodiment of my invention contemplates theslitting of one margin of the strip 12, as indicated in Figure 2. Theslits 14 divide one margin of the strip 12 into a plurality ofadjacently positioned prongs 16. These prongsv are then warped in anysuitable manner, such as by means of dies, out of the plane of the bodyportion 18 of the strip so as to present oppositely disposed workengaging corners 20 on opposite sides of the body 18. I prefer to sowarp or flex the prongs 18 or portions thereof out of the plane of thestock so as to present not only the sharp work engaging corner 20, butalso an elongated work engaging edge corner 20a. In some instances itmay not be necessary to employ the elongated corner presented by theedge 20a, but merely the localized corner or point designated by thenumeral 20. However, my invention contemplates the provision of prongshaving either the edge 20a which extends out of the plane of andparallel with the body of the washer stock, as well as prongs in whichonly the portions 20 project on opposite sides of the stock.

After the prongs 16 have been warped, as indicated in Figure 3, thestock is then edgewise bent, formed or coiled in any suitable manner, asindicated in Figure 4. The edgewise forming of the strip (as shown)causes adjacent portions of the prong to overlap each other. When thestock has been bent sufficiently so as to complete an annular body orwasher 22, it is severed along the line 24, indicated in Figure 5, andthe free edges of the body 18 are secured in abutting relation. In orderto secure the free ends of the annularly formed washer together, Ipropose to spot-weld the adjacent overlapping prongs at 26. Obviouslythe invention is not limited to any particular means for securing thefree ends of the washer body together. In some instances it may be.desirable to change the multi-sided marginal effect shown in the washerof Figure 5 to a true circular form shown in Figure 6. This isaccomplished by subjecting the margin of the body to a suitable swedgingoperation by means'of a die. However, in causing the outer margin of thewasher to conform with a true circle, no variation in the overlappingrelationship of the prongs is occasioned.

In Figures '7 to 9, inclusive, I have shown a -modified constructionwhich is contemplated by the present invention. In Figure 7 a stripdesignated by the numeral 12a is shown, which includes a plurality ofprongs 16a which are separated by notches or slots 14a. The prongs 16aare provided along one margin of a body portion 18a. The prongs 16a, asshown in Figure 8, are warped out of the plane of the body 18a so as topresent work engaging corners 20b, and these corners continue in theform of edges 200, which edges are preferably parallel to the plane ofthe body 18a. After the prongs 16a have been warped, as shown in Figure8, the strip is edgewise formed in the manner shown in Figure 4, so asto present the washer 22a of Figure 9. The edgewise forming of thewarpedprongs 1611 causes them to overlap and present a plurality of workengaging edges 20c projecting out of the plane of and in substantialparallelism with the body 18a, which terminate in the sharp workengaging corners 20b. By having the prongs 16a. and the portion of thebody 18a companion thereto preformed arcuately, as indicated in Figure'7, the resulting structure of Figure 9 will present inner and outermargins which conform with true circles. The adjacent free ends of thewasher 22a are secured together by a spotweld 26a.

In Figures 10 and 11 I have diagrammatically illustrated the manner inwhich a washer constructed in accordance with the teachings of myinvention operate to lockingly engage a work piece. With the exceptionof the two prongs which are welded together, the overlappingrelationship of the remaining prongs will conform with the unfoldeddisclosure of Figure 10. It will be seen that the prongs are axiallyspaced 9. sufiicient distance so that, when the washer is initiallyclamped between a pair of work pieces indicated by the dot-and-dashlines 28, the locking corners of the prongs will resiliently oppose theclamping action. 'If the tightening force is sumcient to overcome theresiliency of the prongs, they will eventually be clamped against eachother in the overlapping relationship shown in Figure 11., In thisrelationship each prong forms a bearing surface for the other, therebyforming a plurality of oppositely disposed work engaging corners, whichrigidly imbed themselves within the work pieces. That is to say, theadjacent overlapping surfaces of the prongs cooperate to produce a rigidlocking element, as distinguished from a resilient or yieldable lockingelement. However, the inherent characteristic of the prongs to springaxially in the event that either work piece tends to loosen, serves tomaterially increase the locking effectiveness of the washer.

As an example of the type of washer which may be produced by practicingmy improved method, I make reference to the overlapping prongarrangement shown in the Murphy Patent 261,947 particularly Figure 3thereof.

In the claims attached hereto reference is made to the disposition ofprongs along the margin bearing such relation to the radius of thefinished washer as to effect an overlapping relationship of adjacentprongs. Obviously when the prongs are actually spaced along the marginof the washer body, as shown in Figure 9, the overlapping of the prongsis dependent upon three factors, namely the width of the space betweenthe prongs, the radial length of the prongs and the radius of thefinished washer. When the prongs are fonned as indicated inFigure 2 byprovidinga plurality of slits or severanc'es, the slightest edgewiseforming of the strip will cause an overlap of the prongs. Therefore,in.order to define methods wherein the prongs are disposed along themargin either by the slits 14 of Figure 2 or notches 14a of Figure 7,all the claims include the above mentioned statement relating to thedisposition of the prongs with relation to the radius of the finishedwasher. This also serves to clearly distinguish from prior methods ofedgewise forming strip stock as shown in the patents to Hosking,1,845,272 and 1,866,304.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. The method of producing washers which includes the step of edgewiseforming into an annular shape a strip of resilient metal having aplurality of prongs along the margin thereof, the disposition of theprongs along the margin bearing such a relation to the radius of thefinished washer as to efiect an overlapping rela-- tionship of adjacentprongs.

2. The method of producing washers which includes the step of edgewiseforming into an annular shape a strip of resilient metal having aplurality of prongs along the margin warped out of the plane of thewasher stock, the disposition of the prongs along the margin bearingsuch a relation to the radius of the finished washer as to effect anoverlapping relationship of adjacent prongs.

3. The method of producing washers which includes the step of edgewiseforming into an annular shape a strip of resilient metal having aplurality of prongs along the margin warped out of the plane of thewasher stock, the disposition of the prongs along the margin bearingsuch a relation to the radius of the finished washer as to effect anoverlapping relationship of adjacent prongs with oppositely disposedcorners on each prong projecting on opposite sides of the plane of thewasher body.

4. The method of producing washers which includes the step of edgewiseforming into an annular shape a strip of resilient metal having aplurality of prongs along the margin warped out of the plane of thewasher stock, the disposition of the prongs along the margin bearingsuch a relation to the radius of the finished washer as to efiect anoverlapping relationship of adjacent prongs with oppositely disposededges of each prong spaced from and in substantial parallelism with theplane of the washer body.

5. The method of producing washers which consists in forming along atleast one margin of a strip of resilient flat stock a plurality ofprongs, and then edgewise forming the strip into an annular shape withvthe prongs along the inner margin, the disposition of the prongs alongthe margin bearing such a relation to the radius of the finished washeras to cause said prongs to overlap during the edgewise forming.

6. The method of producing washers which consists in forming along atleast one margin of a strip of resilient flat stock a plurality ofprongs, then edgewise forming the strip into an annular shape with theprongs along the inner margin, the disposition of the prongs along themargin bearing such a relation to the radius of the finished washer asto cause said prongs to overlap during the edgewise forming, andsecuring together the free extremities of the annularly formed strip.

7. The method of producing washers which consists in severing at spacedintervals a margin of strip stock so as to present a plurality ofadjacently positioned prongs, warping said prongs so as to positionoppositely disposed corners of each prong out of the plane of theunsevered portion of the strip stock, and then edgewise forming intoannular shape the pronged strip,

the disposition of the prongs along the margin bearing such relation tothe radius of the finished washer as to thereby effect an overlappingrelationship of the adjacent prongs.

8. The method of producing washers which consists in severing at spacedintervals 2. margin of strip stock so as to present a plurality ofadjacently positioned prongs, warping said prongs so as to positionoppositely disposed corners of each prong out of the plane of theunsevered portion of the strip stock, edgewise forming into annularshape the pronged strip, the disposition of the prongs along the marginbearing such relation to the radius of the finished washer as to therebyeifect an overlapping relationship of the adjacent prongs, severing theannularly formed strip from the main body of the strip, and thensecuring together the free extremities of said annular member.

9. The method of producing washers which consists in forming a pluralityof prongs along the margin of a strip of resilient stock, warping saidprongs so as to project oppositely disposed work engaging marginsthereof out of the plane of the washer stock, and then forming the stripinto annular shape, the disposition of the prongs along the marginbearing such a relation to the radius of the finished washer as toexperience an overlapping relationship as a result of the annularforming of the strip.

CARL G. OLSON.

